Boron trifluoride etherate → HCID 21835229, compound

Participants

Reaction Conditions

Reaction Steps

A dry flask under N2 was charged with THF (50 ml) and n-butyllithium (13 ml, 0.021 mol, 1.6 M solution in hexanes) and cooled to -78° C. Triethylsilylacetylene (3.0 ml, 0.021 mol) was added dropwise and the reaction stirred for 0.5 h. Distilled boron trifluoride etherate (3.03 ml, 0.025 mol) was then added and the reaction stirred at -78° C. for a further 10 min. The epoxide (step a) was then added as a solution in THF (20 ml) and the reaction stirred for 0.75 h. The reaction was quenched by the addition of saturated NH4Cl and extracted into ethyl acetate. The organic layer was dried over MgSO4 and evaporated in vacuo. The residue was taken up in dioxane:water (1:1, 100 ml) and triethylamine (2.0 ml, 0.0145 mol) added followed by tert-butyldicarbonate (3.0 g, 0.0145 mol). The reaction was stirred for 1h, the dioxane evaporated and the residue partitioned between ethyl acetate and saturated NH4Cl. The organic layer was collected, dried over MgSO4 and evaporated. The residue was chromatographed on silica eluting with ethyl acetate:hexanes (1:9→2:8) to obtain the alcohol as a colourless oil (2.4 g, 49%). 1H NMR (250 MHz, CDCl3) δ 0.58 (6H, q), 0.95 (9H, t), 1.08-1.16 (3H, m), 1.45 (9H, s), 1.59-1.78 (4H, m), 2.35 (1H, dd), 2.47 (1H, dd), 2.73 (2H, t), 4.12 (3H, m).

Provenance & Evidence